handle Lua AtExpressions in xml

stepmania/src/DifficultyIcon.cpp

@@ -10,6 +10,7 @@
 #include "Trail.h"
 #include "ActorUtil.h"
 #include "XmlFile.h"
+#include "LuaManager.h"
 
 REGISTER_ACTOR_CLASS(DifficultyIcon)
 
@@ -45,8 +46,12 @@ void DifficultyIcon::LoadFromNode( const RString& sDir, const XNode* pNode )
 	if( !pNode->GetAttrValue( "File", sFile ) )
 		RageException::Throw( "MeterDisplay in " + sDir + " missing File attribute" );
 
+	LuaHelpers::RunAtExpressionS( sFile );
+	if( !sFile.empty() && sFile[0] != '/' )
+	{
 		sFile = sDir + sFile;
 		ActorUtil::ResolvePath( sFile, sDir );
+	}
 
 	Load( sFile );
 

stepmania/src/MeterDisplay.cpp

@@ -43,8 +43,12 @@ void MeterDisplay::LoadFromNode( const RString& sDir, const XNode* pNode )
 		if( !pNode->GetAttrValue( "StreamPath", sStreamPath ) )
 			RageException::Throw( "MeterDisplay in " + sDir + " missing StreamPath attribute" );
 
+		LuaHelpers::RunAtExpressionS( sStreamPath );
+		if( !sStreamPath.empty() && sStreamPath[0] != '/' )
+		{
 			sStreamPath = sDir + sStreamPath;
 			ActorUtil::ResolvePath( sStreamPath, sDir );
+		}
 
 		m_sprStream.Load( sStreamPath );
 		m_sprStream->SetZoomX( m_fStreamWidth / m_sprStream->GetUnzoomedWidth() );